Biomedical subjects

K Dohi

Publications and source records attributed to K Dohi.

At least 19 recordsLinked to original sources

PubMed1999

A long-term culture of human hepatocytes which show a high growth potential and express their differentiated phenotypes.

The present study succeeded for the first time in cultivating for more than 2 months human normal hepatocytes which showed a high growth potential and expressed their differentiated phenotypes. Constituents of culture medium were critical for this culture, and the medium optimized for their growth contained fresh human serum, fetal bovine serum, Swiss 3T3-cell conditioned medium, L-ascorbic acid 2-phosphate, epidermal growth factor, nicotinamide, and dimethyl sulfoxide. Hepatocytes steadily replicated and formed colonies which continued to increase in size up to around 35 days. The number of hepatocytes in the most replicative colonies increased 17-fold during 31 days. Cells in colonies expressed normal differentiated hepatocytic phenotypes for as long as 35 days. These hepatocytes retained normal liver functions at least for 70 days such as to secrete albumin, and to metabolize lidocaine and D-galactose.

3T3 Cells↗

PubMed1999

Delayed neuronal cell death in the rat hippocampus is mediated by the mitogen-activated protein kinase signal transduction pathway.

Transient global ischemia caused by 5 min of cardiac arrest induced delayed neuronal cell death (apoptosis) in the CA1 region of the rat hippocampus. To characterize the molecular mechanisms that regulate apoptosis in vivo, the contributions to cell death of mitogen-activated protein kinase family members were examined in the hippocampal region after brain ischemia-reperfusion. Ischemia-reperfusion led to a strong activation of the JNK/SAPK (c-Jun NH2-terminal protein kinase/stress activated protein kinase), ERK (extracellular signal-regulated kinase), and p38 enzymes. These results with other previous studies suggest that the activation of JNK/SAPK in accordance with p38 contributes to the induction of apoptosis in CA1 neurons.

Animals↗

PubMed1999

Increased urinary levels of adrenomedullin in patients with cystitis.

In this study, we examined urinary levels of adrenomedullin (AM) in 18 healthy volunteers and 18 patients with cystitis. We also compared urinary levels of AM in 11 patients with cystitis before and after antibiotic treatment. Urinary AM concentrations were measured by a radioimmunoassay specific for human AM. Urinary AM levels in patients with cystitis were significantly elevated compared with those of healthy volunteers and correlated positively with the number of urine leukocytes. By antibiotic treatment, urinary AM levels significantly decreased as compared with before the treatment. By RNA blot analysis of AM transcript, we detected significant levels of AM mRNA in canine urinary bladder and ureter. Intravenous administration of lipopolysaccharide elevated the AM mRNA level in the urinary bladder. These data suggest that infection and inflammation stimulate AM production in the urinary tract, which results in increased urinary AM levels in patients with cystitis. Based on these results, it is deduced that AM participates in the pathophysiology of cystitis, and its urinary level could be used as an index of the degree of cystitis.

Adrenomedullin↗

PubMed1999

Analysis of the c-myc, K-ras and p53 genes in methylcholanthrene-induced mouse sarcomas.

We have examined 63 methylcholanthrene (MCA)-induced mouse sarcomas for possible correlations of mutations involving the c-myc, ras and p53 genes. The c-myc gene was found to be amplified in 18 of these sarcomas (29%). Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis and subsequent direct sequencing identified 18 cases carrying K-ras mutation at codons 12, 13 and 61 (29%). No mutation was detected in the H-ras and N-ras genes. Mutations of the p53 gene in exons 5 to 8 were found in 45 cases (71%). Comparison of these mutations revealed that out of 18 cases with c-myc gene amplifications, 10 carried K-ras mutations (56%) and 14 carried p53 mutations (78%). In contrast, among 45 cases of sarcomas without c-myc gene amplification, 8 were found to have K-ras mutations (18%). The same 45 cases were found to have 31 p53 mutations (69%). The present study suggests a strong correlation between c-myc gene amplification and K-ras gene mutation (P < 0.01). p53 gene mutation was frequently found among MCA-induced mouse sarcomas, indicating the importance of this mutation in the etiology of these tumors. However, p53 mutations were present in sarcomas regardless of the state of c-myc amplification and K-ras mutation. Therefore, a defect in the p53 gene is independent of amplification of the c-myc gene or point mutation of the K-ras gene.

Animals↗

PubMed1999

A case of eosinophilic myocarditis complicated by Kimura's disease (eosinophilic hyperplastic lymphogranuloma) and erythroderma.

This report describes a patient with eosinophilic myocarditis complicated by Kimura's disease (eosinophilic hyperplastic lymphogranuloma) and erythroderma. A 50-year-old man presented with a complaint of precordial pain. However, the only abnormal finding on examinatioin was eosinophilia (1617 eosinophils/microl). Three years later, the patient developed chronic eczema, and was diagnosed with erythroderma posteczematosa. One year later, a tumor was detected in the right auricule, and a diagnosis of Kimura's disease was made, based on the biopsy findings. The patient developed progressive dyspnea 6 months later and was found to have cardiomegaly and a depressed left ventricular ejection fraction (17%). A diagnosis of eosinophilic myocarditis was made based on the results of a right ventricular endomyocardial biopsy. The eosinophilic myocarditis and erythrodrema were treated with steroids with improvement of both the eosinophilia and left ventricular function.

Angiolymphoid Hyperplasia with Eosinophilia↗

PubMed1999

Relationship between brain atrophy estimated by a longitudinal computed tomography study and blood pressure control in patients with essential hypertension.

To evaluate the relationship between blood pressure control and the progression of brain atrophy in the elderly, patients with essential hypertension and brain atrophy were longitudinally evaluated using computerized tomography (CT). The study evaluated 48 patients with essential hypertension aged 46-78 years, and 30 sex- and age-matched normotensive control subjects. The extent of brain atrophy as determined by caudate head index (CHI), the inverse cella media index (iCMI), and Evans' ratio (ER) was estimated twice at an interval of 5-9 years (mean, 6.9 years). The mean annual increases in CHI (deltaCHI), iCMI (delta iCMI), and ER (deltaER) were evaluated. Mean blood volume in the common carotid artery (BF) and the decrease in BF per year (deltaBF) were also determined. The deltaCHI, delta iCMI, and deltaER increased with age in the hypertensive subjects as well as the control group across all age groups evaluated. The deltaCHI, delta iCMI, and deltaER were significantly greater in the patients with essential hypertension in their 50 s as compared with the controls. In patients with essential hypertension aged 65 years or older, the deltaCHI, delta iCMI, and deltaER were significantly lower in the group in whom the blood pressure was controlled within the range of borderline hypertension than the groups in which it was controlled in the range of normal or mild hypertension. In the younger patients under the age of 65 with essential hypertension, blood pressure control did not affect the deltaCHI, delta iCMI, and deltaER. The deltaCHI, delta iCMI, and deltaER were significantly correlated with deltaBF in both groups. These findings indicate that control of systolic blood pressure within the range of borderline hypertension may delay the progression of brain atrophy in elderly patients with essential hypertension.

Aged↗

PubMed1999

Close correlation between a p53 or hMSH2 gene mutation in the tumor and survival of hepatocellular carcinoma patients.

We analyzed 42 hepatocellular carcinomas (HCC) (38 patients) for mutations in the DNA mismatch repair gene hMSH2 and the p53 tumor suppressor gene, a possible upregulater of hMSH2. Mutations of the hMSH2 or p53 gene were detected in 13 patients (34%). There were no patients who possessed mutations in both genes. There was a significant correlation between mutation of either gene and pathological indicators of malignancy. The survival rate of patients with hMSH2 or p53 gene mutation-positive tumors was much poorer than that with hMSH2 and p53 gene mutation-negative tumors (p=0.0012). Our results suggest that mutations in the p53 or hMSH2 gene may closely correlate with the survival of hepatocellular carcinoma patients.

Carcinoma, Hepatocellular↗

PubMed1999

Association of an insertion polymorphism of angiotensin-converting enzyme gene with the activity of lupus nephritis.

BACKGROUND: Lupus nephritis is a common manifestation of systemic lupus erythematosus (SLE). The pathogenesis of lupus nephritis has not been fully understood; however, immunological abnormalities have been considered in the development and activity of lupus nephritis. As angiotensin-converting enzyme (ACE) is implicated in various immunological phenomena, we investigated the correlation between insertion (I)/ deletion (D) polymorphism of the ACE gene and the activity of lupus nephritis. PATIENTS AND METHODS: Eighty-four patients with SLE and 100 healthy subjects were enrolled in this study. Following the extraction of genomic DNA from the peripheral blood, the ACE genotype was determined by the polymerase chain reaction. The patients were classified by the histological findings according to the WHO classification. In addition, the activity index and chronicity index were used to assess the severity of renal involvement. RESULTS: Individuals with II genotype showed a significantly increased activity of lupus nephritis. The allelic frequency was I/D = 0.84/0.16 in patients with WHO class IV renal lesions, and I/D = 0.36/0.64 in those with WHO class I lesions and 0.61/0.39 in patients with WHO class I or WHO class II. The difference in the allelic frequency between patients with WHO class IV and those with WHO class I or WHO class I + WHO class II was statistically significant (p = 0.00016 or p = 0.027, respectively). Moreover, lupus nephritis patients with II genotype showed significantly higher activity index than those with DD genotype (p = 0.0009). CONCLUSION: These results suggest that the insertion polymorphism of the ACE gene may correlate with the activity of lupus nephritis.

Adult↗

PubMed1999

[Transnasal microsurgery using a micro-pressure-suction-irrigation system for pituitary adenomas].

Micro-pressure-suction-irrigation system (MPSIS), introduced by Luedecke et al, is an instrumentation for the direct transnasal pituitary procedure. We improved this system for use in Japan. The irrigation system can effectively clean the operating field by one-hand manipulation and dissect tumor tissue by its rapid flow. The pressure of suction and irrigation can be adjusted respectively by a device in the handpiece. The MPSIS is applicable to different stages of intervention because it is equipped with separate tips of various diameters, lengths and angles. This system is especially useful in combination with a micromirror or an endoscopy for direct inspection of the eccentric tumor sites such as the cavernous sinus, the upper part of the planum sphenoidale, or the posterior suprasellar regions. The use of the MPSIS helps to avoid injury to normal tissue structures, and prevents tiny soft microadenoma from being lost during preparation. We have proved the suitability and usefulness of the MPSIS in 23 surgical interventions for transnasal microsurgery of pituitary adenomas.

Adenoma↗

PubMed1999

Granular cell tumor of the breast: report of a case.

A case of granular cell tumor of the breast in a 43-year-old woman is described. The patient presented with a painless mass in the upper-outer quadrant of her right breast. Mammography showed a spiculated tumor and ultrasonography demonstrated a hypoechoic mass with an irregular border. Magnetic resonance (MR) mammography revealed a homogeneous enhanced mass in T1-weighted images using Gd-DTPA and a ringed high-intensity area around the mass in T2-weighted images. Fine-needle aspiration cytology failed to show any malignant cells. A partial resection of the breast was performed and histological examination revealed a granular cell tumor. Granular cell tumors are generally always benign, but they may be misdiagnosed as malignant tumors because of their mammographic and ultrasonographic findings. MR mammography did not reveal a typical breast cancer in either T1- or T2-weighted images in the present case. This case illustrates the need for care in preoperative examinations in order to avoid overdiagnosis of breast cancer.

Adult↗

PubMed1999

A case of hepatocellular carcinoma with bone metastasis responding to radiotherapy after successful hepatectomy of primary lesion.

Radical hepatectomy was carried out on a patient with hepatocellular carcinoma (HCC) located in segment VIII of the liver. The patient was a 56-year-old man who showed positive for hepatitis C antibody and negative for hepatitis B surface antigen. Six months after hepatectomy, a lumbar plane X-ray and computed tomography examination revealed bone metastases in the lumbar vertebrae. The patient was subsequently treated by radiation to the lumbar vertebrae in response to lumbago. The metastatic lesion has been well controlled by radiotherapy on an outpatient basis with no recurrence for 5 years and 3 months. The prognosis of patients with HCC with distant metastases is poor. It is believed that the long survival of this patient can be attributed to successful radiotherapy of the bone metastasis after hepatectomy and the lack of recurrence in the liver.

Aged↗

PubMed1999

A patient with a large hepatocellular carcinoma alive 13 years after repeated transcatheter arterial chemoembolization and hepatectomy.

We describe a rare case of a large hepatocellular carcinoma (HCC) in a patient who survived 13 years after repeated transcatheter arterial chemoembolization (TAE) and hepatectomy. The patient was a 41-year-old woman found in March 1985 to have a large HCC, measuring 14 x 12 cm in diameter and associated with obstruction of the main portal trunk. She underwent TAE 8 times over a period of 1 year. The serum alpha-fetoprotein level decreased from 18342 to 1871 ng/ml. The patient subsequently underwent left hepatectomy on October 9, 1986. Thirteen years after hepatectomy, the patient is being followed up on an outpatient basis and has had no evidence of recurrence.

Adult↗

PubMed1999

A case of biliary cystadenocarcinoma of the liver.

We describe a case of biliary cystadenocarcinoma of the liver, a very rare malignant tumor, in a 40-year-old man referred to our hospital because of sporadic abdominal pain. A left lobectomy of the liver was performed, and macroscopic examination of the resected specimen revealed prominent papillary projections in a multiloculated cystic tumor containing mucinous material. Histologic examination of the specimen showed a biliary cystadenocarcinoma without mesenchymal stroma, associated with a cystadenoma. Cystadenoma with mesenchymal stroma (CMS), which occurs exclusively in women, is generally regarded as a precancerous lesion, and patients with biliary cystadenocarcinoma with mesenchymal stroma have a good prognosis. Cystadenoma without mesenchymal stroma arises in both men and women. However, the origin and precancerous lesions of cystadenocarcinoma are unknown. Moreover, the prognosis of patients with biliary cystadenocarcinoma without mesenchymal stroma is poor, especially in men. The cystadenoma without mesenchymal stroma in our patient was considered a precancerous lesion. The present patient has shown no evidence of recurrence in the 8 years after hepatic resection. Previously reported cases of cystadenocarcinoma without mesenchymal stroma, especially those in men, have had a poor outcome. A good outcome in men is very rare.

Adult↗

PubMed1999

Effect of lazaroid U-74389G and methylprednisolone on endotoxin-induced shock in mice.

BACKGROUND: Lazaroids are nonglucocorticoid analogs of methylprednisolone with multiple actions. We investigated whether lazaroid U-74389G could attenuate endotoxin-induced liver injury. We hypothesized that U-74389G treatment may protect against hepatic injury by suppressing proinflammatory gene up-regulation through inhibition of activation of nuclear factor kappa B (NF-kappa B). We also compared the efficacy of U-74389G with methylprednisolone in endotoxin-induced liver injury. METHODS: Lipopolysaccharide (Escherichia coli, 30 mg/kg given intraperitoneally) was administered to male ICR mice, and U-74389G (3 mg/kg intraperitoneally) or methylprednisolone (30 mg/kg intravenously) was administered simultaneously. Phosphate-buffered saline solution (0.15 mL intravenously) was administered to mice that served as a control group. RESULTS: U-74389G and methylprednisolone treatment significantly increased survival rates 48 hours after lipopolysaccharide injection and protected against lipopolysaccharide-induced liver injury in vivo, as indicated by the decreased hepatic lipid peroxidation, tumor necrosis factor-alpha, and inducible nitric oxide synthase messenger RNA formation, hepatic enzyme release, and neutrophil infiltration in the liver. U-74389G and methylprednisolone also showed inhibitory effects on NF-kappa B activation in the liver. CONCLUSIONS: These findings suggest that U-74389G can suppress proinflammatory gene up-regulation through inhibition of NF-kappa B activation and that it is a promising new antioxidant drug for the treatment of endotoxin shock.

Alanine Transaminase↗

PubMed1999

Non-suture end-to-end anastomoses between polytetrafluoroethylene graft and vessels for blood access.

BACKGROUND: Non-suture end-to-end anastomoses between polytetrafluoroethylene grafts and blood vessels were achieved using absorbable cuff material in experimental and clinical studies. The cuff was made of a synthetic biodegradable material, a lactic-glycolic acid copolymer, similar in composition to conventional absorbable surgical sutures. METHODS: In the experimental study, vascular anastomoses for prosthetic interposition of the infrarenal aorta in rabbits were created using the cuff method. Six months after surgery, the cuff anastomoses sites were examined angiographically and microscopically and found to be patent and smooth without neointimal hyperplasia. RESULTS: The cuff layer had been completely absorbed. The clinical application used a similar technique and involved the creation of forearm bridge graft fistula in twelve patients for hemodialysis. In eight patients, Doppler fistula flow rate ranged from 167 ml/min to 392 ml/min. Ten of the twelve patients continued dialysis uneventfully. The one-year patency rate was 78% (7/9). The longest patency period was 920 days and the graft access continued to maintain sufficient blood flow for hemodialysis. CONCLUSIONS: This absorbable cuff material is therefore well suited for the construction of prosthetic vascular end-to-end anastomoses.

Aged↗

PubMed1999

Glomerular hypertrophy in preeclamptic patients with focal segmental glomerulosclerosis. A morphometric analysis.

BACKGROUND: Focal segmental glomerulosclerotic lesion (FSGS lesion) is frequently observed in preeclamptic patients with nephrotic syndrome. PATIENTS AND METHODS: We performed a morphometric analysis of renal biopsies from 20 patients with severe preeclampsia to evaluate the pathogenetic role of glomerular hypertrophy in preeclamptic nephropathy associated with FSGS lesion. We also analyzed biopsies obtained from 6 preeclamptic patients without FSGS lesion and 10 patients with isolated hematuria. Nonsclerotic glomeruli were examined. RESULTS: The mean glomerular tuft area (GTA), the whole glomerular area (WGA), and the extracellular matrix area (EMA) were significantly and negatively correlated with the postpartum day at biopsy in preeclamptic patients with FSGS lesion who underwent renal biopsy within 40 days after delivery. The mean GTA, WGA, EMA and number of mesangial cells (MN) were significantly increased in preeclamptic patients with FSGS lesion compared with patients with isolated hematuria and compared with those without FSGS lesion when the biopsy time was matched between patients with and without FSGS lesion. The GTA and WGA were not different between preeclamptic patients without FSGS lesion and patients with isolated hematuria. CONCLUSION: These results support the assumption that glomerular hypertrophy that develops during severe toxemic pregnancy plays an important role in the pathogenesis of FSGS lesion and is reversible about 40 days after delivery.

Adolescent↗

PubMed1998

PACAP protects hippocampal neurons against apoptosis: involvement of JNK/SAPK signaling pathway.

We have demonstrated that the ischemia-induced apoptosis of neurons in the CA1 region of the rat hippocampus was prevented by either intracerebroventricular or intravenous infusion of pituitary adenylate cyclase-activating polypeptide (PACAP). However, the molecular mechanisms underlying the anti-apoptotic effect of PACAP remain to be determined. Within 3-6 h after ischemia, the activities of members of the mitogen-activated protein (MAP) kinase family, including extracellular signal-regulated kinase (ERK), Jun N-terminal kinase (JNK)/stress-activated protein kinase (SAPK), and p38 were increased in the hippocampus. The ischemic stress had a potent influence on the MAP kinase family, especially on JNK/SAPK. PACAP inhibited the activation of JNK/SAPK after ischemic stress. Secretion of interleukin-6 (IL-6) into the cerebrospinal fluid was intensely stimulated after PACAP infusion. IL-6 inhibited the activation of JNK/SAPK, while it activated ERK. These observations suggest that PACAP and IL-6 act to inhibit the JNK/SAPK signaling pathway, thereby protecting neurons against apoptosis.

Animals↗

PubMed1998

Serum levels of VEGF and basic FGF in the subacute phase of myocardial infarction.

We examined serial changes in serum levels of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) measured by ELISAs in 45 patients with acute myocardial infarction (AMI) who received heparin intravenously for 3 to 5 days after the onset and in 30 control subjects with an old myocardial infarction. To evaluate the effect of heparin on these serum levels, heparin was administered intravenously in 10 patients with AMI on day 21. Blood samples were obtained from all AMI patients on days 1, 2, 3, 7, 14, 21, and 28 and from 10 AMI patients before and 1 h after heparin administration. Serum VEGF level was significantly reduced after heparin administration (P<0.001). Serum samples from day 1 to 3 were therefore excluded from the subsequent analysis. Serum VEGF level in AMI patients was significantly higher on day 7 than in the control subjects (P<0.0001), and then decreased over time (P<0.0001). The serum VEGF level on day 7 was independently associated with the peak serum CK level (P<0.05). The serum bFGF level did not differ significantly between the AMI patients and the control subjects. In conclusion, the serum VEGF level may be selectively elevated during the healing process after AMI.

Anticoagulants↗